They are not of the dc variety. Search these forums for info about dc and you will see that the only ones that work well enough to be used are 100$ and up.
I can and do make relays also. But the resevores come ready to plug into any american 110 volt ac outlet.
The fittings are 5/8 inch for increased flow and work perfectly with silicone or tygon 1/2 inch tubing as that is what I'm using in the pics. Sure I could do a packaged deal email me at
bah@webmedc.net.